Meaning
Regulatory compliance procedures for modern smartphones require adherence to specific test guidelines provided by federal authorities. The guidance known as KDB 648474 D04 provides the test methodology for evaluating specific absorption rate limits in handsets. This document focuses on devices with multiple transmitters and diagonal dimensions exceeding certain thresholds.
It outlines the specific conditions under which antenna positioning and display sizes affect compliance measurements.
Phantom Configuration
Handset evaluation uses both head and body phantoms to simulate real-world usage scenarios. The guidelines in KDB 648474 D04 define the separation distances and the usage of hand phantoms during extremity testing. Testing must be executed with specific accessories like holsters or headsets if they are shipped with the device.
These protocols ensure that exposure measurements capture the maximum possible energy absorption by the user.
Power Scaling
Calculations must account for the maximum rated output power of each transmitter to scale measured SAR values. Following the procedures of KDB 648474 D04, laboratories evaluate each band and technology combination separately. The document specifies how to calculate the sum of simultaneous transmission ratios to determine if stand-alone testing is required for secondary antennas.
This step prevents underestimating the combined exposure from co-located wireless transmitters.
Industry Testing
Certification laboratories apply these criteria to ensure that mobile devices receive official market authorization. Compliance with KDB 648474 D04 is mandatory for filing wireless device applications with the commission.
